My holy grail is the G2 prototypes MOSC...menasor and defensor...
They will literally cost more than 40,000 USD. no joke... I don't know if I ever will have enough money or the stupidity to spend that much money... but you never know...
The last loose motormaster went for 7k+ USD on the bay from memory...
These are some links for the defensor...
http://www.geocities.com/fredsworkshop/g2defensor1a.jpg
http://www.geocities.com/soxerboxx3/defensor4me.jpg
These are in my opinion the absolute HOLY GRAIL for a G1, G2 hybrid collector, simply because they were never released... but a very microscopic handful of collectors do have them.